Two passenger buses collided Saturday on a highway in southern Bolivia, leaving at least 37 people dead including eight minors, police said, in the country's worst bus accident to date this year.

"So far we have 37 confirmed deaths," Colonel Wilson Flores told AFP of the crash near the city of Uyuni in the department of Potosi.

Another 41 people were injured and transported to hospitals, police said.

Six foreigners were among those killed: five Peruvians and a three-year-old German girl. Seven other minors also died.

The accident occurred on a narrow two-way road early Saturday.

One of the buses was heading to the city of Oruro, the scene this weekend of the Oruro Carnival, one of the largest festivals in Latin America that attracts tens of thousands of people.

Potosi prosecutor Gonzalo Aparicio told state-run news agency ABI that the driver of one of the buses had been drinking and was speeding when he strayed into the opposing lane where he crashed into the oncoming vehicle.

"So far it is known that a driver of one of the buses was under the influence of alcohol," he said.

Earlier an official had said one of the drivers, who survived the crash in grave condition, had "alcohol breath," so a blood test was performed.

Bolivia's winding mountain roads are notoriously deadly.

Road accidents kill an average of 1,400 people every year in the country of about 12 million inhabitants, according to government data. 

Potosi accounts for 10.6 percent of all traffic accidents with fatalities in the South American country, according to the Bolivian Observatory of Citizen Security.

Before Saturday's collision, 64 people had died in traffic accidents in Potosi alone this year, according to a police report.

Saturday's accident comes less than two weeks after at least 30 people were killed when a passenger bus plunged into an 800-meter-deep ravine in southern Bolivia. 

The accident happened on a narrow two-way road between the cities of Potosi and Oruro, with the route running along a ravine nearly half a mile deep. 

Authorities said the crash was potentially caused by speeding, with the driver unable to control the bus.

In January, another nineteen people were killed when a bus careened off a road, also near Potosi.

The driver in that accident was arrested on suspicion of dangerous driving causing fatalities.